$\left[\begin{array} {ccc} -5& 2& 3\\ 1& 4& -8\\ 5& 0& 2\\ 7& 0& -3 \end{array}\right]$ What are the dimensions of the matrix?
Answer: The first dimension is the number of rows in the matrix. There are $4$ rows. The second dimension is the number of columns in the matrix. There are $3$ columns. In conclusion, the dimensions of the matrix are $4\times 3$.